Wednesday, 22 July 2009

Up in smoke

How many people are cremated each year and how much energy is consumed in the process? Will these numbers increase on current projections? And are there no better and environmentally friendly methods of disposal?

Wakey wakey

Pretty in pink

Why are girls, and particularly young girls, drawn to the colour pink? Is it something society has instilled in them? Or is there something attractive about the colour itself? Shops seem to be full of pink clothes for young girls - are they reacting to demand or just forcing their designs upon children who would not otherwise choose this colour?

Wednesday, 3 June 2009

Taste tribulation

This is a question that my husband, Jon Richfield, cannot answer to my satisfaction. I find the taste of certain common spices quite horrible. The nasty flavour I get from all of them seems, to me, quite similar.

The spices that taste this way are aniseed, caraway, cumin, fennel and coriander. Tarragon, cardamom and capers also taste awful in the same way.

I wonder if there is a food scientist who knows what they have in common, or what my aversion might be. I should add that I am not a fussy eater in general.

Wheels of death

I heard the car is the deadliest weapon created by humans and that the number of lives it has claimed exceeds the death toll from atomic weapons, guns or bombing. Is this true? And what are the grisly figures involved?

Wednesday, 1 April 2009

Swallow your pride

I've just seen a sword-swallowing act. Swords, seemingly longer than the depth from throat to anus were swallowed. It has to be a trick, doesn't it? If it is, what's the trick? If it isn't, what's going on?

Wednesday, 11 March 2009

Ride the curves

Why are velodromes shaped the way they are? What's the science involved?

Specifically, why do they have such high curves, especially as hardly any cyclists seem to venture up there, and why do they have sloping straights? Also, what are the different coloured lines on the track for?

Form is temporary

Twice at the weekend I went out running. I ran at the same time on both days and for the same distance. I slept well the night before both runs, ate similar meals, drank the same amount of liquid and felt generally fine on both days.

On the first day I bounced along, running as well as I would expect. On the second day it felt like I was running through treacle; I was lethargic and it was dreadfully hard work.

I haven't subsequently gone down with any illness, so why did this happen?

Smells fine to me

I recently bought a spray-on deodorant. When I got it home I realised it was intended for women but, not wanting to waste money, I used it anyway. Nothing untoward happened and I received no strange looks from colleagues or friends. So what are the differences between deodorants meant for men and those that are meant for women? How might using the "correct" deodorant for your sex work better than using one meant for the opposite sex, and what are the pitfalls of applying a deodorant intended for the opposite sex?

Wednesday, 4 February 2009

Partial recall

Sometimes during a quiz, we know that we know the answer to a question even though we can't bring it immediately to mind. How?

Here's an example. Question one: what is the capital of France? I immediately know that the answer is Paris. Question two: what is the capital of Uzbekistan? I immediately know that I do not know the answer. Question three: what is the capital of Portugal? I know that I have the answer in my brain, but I can't quite remember it. Then, as the answer is read out, I agree that it is Lisbon.

In some cases, for hours afterwards I know that I know the answer to something but can't recall it. So how is it that I can know that I know the answer to a question but, despite that, still cannot retrieve that piece of information?

Wednesday, 28 January 2009

Shampoo pooh-pooh

I have just read the label on my shampoo bottle. The list of ingredients is mind-boggling. How on earth did anyone come up with such a complex concoction and what exactly are chemicals such as sodium diethylene-triamine pentamethylene phosphonate and hydroxyisohexyl 3-cyclohexene carboxaldehyde doing to my hair?

On a high

A number of athletics and cycling world records have been set at high-altitude venues, for example during the 1968 Olympic Games in Mexico City. Presumably the air is thinner so there is less resistance, enabling them to run or cycle faster. But surely oxygen uptake at altitude is more difficult, so there must be a point at which altitude no longer favours athletes.

What is this point and why? And which tracks or velodromes come nearest to it?

Wednesday, 14 January 2009

Studying form

When closely matched athletes are competing in events that involve running, swimming, throwing or lifting, why does one of them win one day and another the next? Surely whoever is the fastest or strongest will remain so, for a while at least. Often the original winner will return a few days later and win again, so why did he or she lose the race between the two victories?

Can't face it

Wednesday, 7 January 2009

Eye level

The eye views images upside-down in the manner of a camera lens, but our brains reinterpret this input to allow us to see things the correct way up. Have there been any examples of damage to this part of the brain, causing people to see the world upside down? How does this happen, is the brain able to compensate and if so, how?Kel, Gladesville, New South Wales, Australia

Wednesday, 31 December 2008

Hot to trot

Mustard and chillis are both hot, but the burning sensation from a chilli stays in the mouth for ages while the sensation from hot mustard disappears in a few seconds. Why is this?Dominic Lopez-Real, no address supplied

Soda soother

Whenever I burn myself, I use my grandmother's old remedy to help relieve the pain and cool the wound: bicarbonate of soda, mixed with a little water and applied directly to the affected area. It works, but how?Alexandra Winter, Dundee, UK

Wednesday, 3 December 2008

A matter of timing

When I use a stopwatch to time events, I know that the accuracy of the result is subject to my ability to stop the watch at the correct instant. I am also aware that I must often be at least a few hundredths of a second out.

Before the advent of electronic timing, world records such as those in athletics or swimming were measured with manual stopwatches. How accurate were these timings? Was more than one watch used and how did officials ensure they were as accurate as possible?

Wednesday, 26 November 2008

In the clink

My father-in-law used to tape family mealtime conversations. When played back, the background noise - like silverware hitting plates and doors closing - is surprisingly prominent. Why is it that we filter these sounds out as they happen, but seem unable to filter them out when we listen to the recording?Gary Yane, Oldenburg, Indiana, US

Hair-raising event

Walking along the breakwater at Berwick-upon-Tweed in north-east England recently, my granddaughter and her mother noticed their hair was standing on end (see photo, above left). It started to rain soon afterwards, but there was no thunder or lightning that day. What was happening?

Fat chance

During a recent health check, the scales I was weighed on also gave a read-out of the percentage of my weight that was body fat. The scales had a pair of metal plates which I had to stand on with bare feet while gripping an electrode in each hand. How do they work?

Wednesday, 19 November 2008

Cavorting cavities

I have often noticed that my fillings feel a bit strange when I'm bouncing on a trampoline. Several other people I know also report this. Oddly, it doesn't happen on the landing, when I am experiencing greatest deceleration, but on the apex of a bounce, at the point when I am momentarily weightless or just beginning to fall.

What causes this? Does anybody know if jumping astronauts notice any filling-based irritation while horsing around in zero gravity?

Wednesday, 12 November 2008

Reverse charge

Having watched high jumpers in slow motion, I cannot work out why it is easier to jump over a high-jump bar backwards using what was originally the "Fosbury flop" technique that was introduced in 1968, than it is to go forwards over the bar. What facets of human mechanics enable jumpers to jump higher when travelling backwards?

Track challenge

It must be easier to run in a straight line than it is to run around a bend. And the tighter the bend, presumably, the slower you have to run.

In a standard Olympic 400-metre race, run in lanes, the staggered starts are presumably arranged so that the competitors all run exactly 400 metres. What disadvantages do runners on the inside lanes face? It seems unlikely that they can ever run as fast as the athletes in the outside lanes.

Jump start

A sprint athlete is deemed to have false-started if they react within 0.1 seconds of the starting gun. This seems like a rather arbitrary round figure. What studies have been done to test human reaction times, and is the fastest a person can react to the sound of a gun really exactly 0.1 seconds?

Wednesday, 29 October 2008

Fungal goodness

We are constantly being exhorted to eat five servings of fruit or vegetables a day, cut down on red meat, eat more fish and so on. But very few mention that other kingdom of gastronomic delights, fungi. What nutritional value does your average edible fungus have?

Wednesday, 24 September 2008

Don't think about it

As a secretary, my job involves a lot of typing. If I am not concentrating on what I am doing, I can type very quickly and accurately, but as soon as I think about it, where the keys are, for example, I type like a fool, extremely slowly and with numerous errors. The same applies to plenty of other activities, such as playing the piano, driving a car, even reading and talking. If you think about what you are doing you do it less efficiently. Why?

Wednesday, 13 August 2008

Transient taste

For the past few days I have experienced a bitter taste in my mouth after eating or drinking. This persists for a while, gradually fading until I eat something else. In my researches to find a cause, I have learned that for some people eating certain varieties of pine nut can alter the sense of taste for days or even weeks. How can they do this and why does the effect last so long.

Wednesday, 6 August 2008

Beat generation

Most music is written in 4/4 meter, giving four beats per bar. Why are we inclined to prefer 4/4 time? Are there circuits in our brains that tick along in patterns of four?

Michael Light, Carlisle, Western Australia

Lots of debate here about whether rhythmic choice is nature or nurture, as you'll see below. Marching may be the origin of the 4/4 meter, but it is clearly only part of the story, for the reasons outlined in the final contribution - Ed

Bags of sleep

Tuesday, 3 June 2008

Toilet training

Ever wondered how best to relieve yourself in the countryside? Then read Last Word editor Mick O'Hare's guest blog on the Farmers Weekly site, in which he returns to the scatological territory previously covered by this Last Word question.

Wednesday, 30 April 2008

Chain gang

My father used to hang a chain which dragged along the road from the back of our car. He said it would prevent my sister from getting car sick. I thought it was some kind of placebo effect but later I discovered that my husband's family did this for their car-sick dog. Does it work and, if so, how?Ginette Andress, Allambie Heights, New South Wales, Australia

Finger clickin' good

Wednesday, 12 March 2008

Ocker stopper

In Australia, the loud, shrill call of "Cooee!" is often used over long distances in rural and mountainous areas to draw attention to oneself. What is it about this word that makes it more audible over distance and is there a word more suited to drawing attention to myself should I be lost in the outback?

Wednesday, 5 March 2008

What's the crack?

I regret to say that I have a habit of cracking my knuckles. I’ve read somewhere that it does no harm, but I am still far from convinced. Could it be damaging in the long run? If so, why?Alex Cowley, Worthing, West Sussex, UK

Rose-tinted vision

If I look out of my left eye, everything is tinted slightly green. From my right eye, everything is tinted slightly red. When I look out of both eyes at the same time, the image produced is uniform and untinted. Why is this?

Wednesday, 20 February 2008

Nocturnal alignment

Assuming a person is totally healthy, is there any physiological reason for a person's preferred sleeping position? My husband likes to sleep with his arm under the pillow, but if I do this, not only do I find it terribly uncomfortable but my arm goes numb within minutes! I always go to sleep on my side but wake up on my back. Why would I find going to sleep on my side more comfortable when my body obviously prefers to sleep on its back?

Wednesday, 9 January 2008

No swimming

Everyone I know was told as a small child not to swim within an hour of eating. Why is this?

Louis Counter, Croydon, Surrey, UK

Several people suggested that this is a groundless old wives' tale, although our understanding of physiology suggests otherwise. A few pointed to carbohydrate loading, performed by marathon runners before a race, as evidence that the body copes well with eating and exertion after only a short interval. The question is, how short should that interval be? See Jon Richfield's answer below - Ed

Eye liner

Make a pinhole in a piece of cardboard. Bring your eye close to it and look through the pinhole as you rotate the card. You will see the network of your retinal capillaries against the background of a cloudy sky. How does this happen?

Wednesday, 12 December 2007

Filthy lucre?

Can viruses and bacteria be transmitted on coins or notes, which pass through so many hands? What is the likelihood of catching something unpleasant from money, and if it does harbour disease, what might I catch? Finally, what is the average number of germs likely to be hitching a ride on coins or paper money?

Michaela Lanzarotti, Pesaro, Italy

Viruses can survive on banknotes, as scientists in Switzerland recently showed when they dripped flu virus onto notes accompanied by human nasal mucus. The viruses remained viable for up to 17 days (see www.newscientist.com/channel/health/dn12116) - Ed

Wednesday, 28 November 2007

Blow it out

Right now I have a cold. After blowing my nose for what seems like the millionth time, I wondered just how much mucus the nose produces during the average cold, and does its loss mean I lose any substantial amount of weight?

Wednesday, 7 November 2007

Counter-taserism

At the recent conference of the Police Federation of England and Wales there was a call for the increased use of tasers (and, of interest to etymologists, the appearance of the verb "to tase"). Purely in the interests of research, what could be done by an individual to lessen the effect of being tased? What happens if the tased person grabs the officer who has fired the taser? If the tasee is wearing rubber-soled shoes, will that help? Alternatively, if they are standing in a puddle, will that worsen the effect? And what would a master criminal need to become invulnerable to tasing - a full-body rubber suit?Adil Hussain, Birmingham, UK

Tuesday, 30 October 2007

Eye for the pink

I have just found this illusion online (click the image to see it). If you follow the movement of the rotating pink dot, it remains pink. However if you stare at the black cross, the moving dot appears green. If you concentrate on the black cross for a while, all the pink dots will slowly disappear, leaving only a rotating green dot.

There is no green dot, and the pink dots don't disappear. How does this work?

Wednesday, 24 October 2007

Finger Roll

Why is it that regardless of whether you are left-handed, right-handed or ambidextrous, you find it much easier to drum your fingers starting with your little finger rather than your forefinger?Dave Scates, Pyrfod, Surrey, UK

Thanks to all of those who offered anatomical explanations, but it seems that they are misplaced. We have uncovered an important subset of the population, some of whom are clearly in need of reassurance - Ed

Wednesday, 26 September 2007

Keep focused

I am short-sighted. However, if I remove my glasses and peer through a tiny hole made between my fingers, or a pinhole in a piece of card, I can read signs from an even greater distance than with my glasses on. Why is that?Rodney McManaman, Whitehaven, Cumbria, UK

Wednesday, 15 August 2007

Human zoo

If aliens wanted to create new human pet breeds using only selective breeding, what traits would they find easiest or hardest to alter and what kind of timescales would be involved? Would we be easier or more difficult to breed selectively than, say, dogs?Gerry Walsh, Maynooth, Kildare, Ireland

Wednesday, 1 August 2007

Underground reservoir

Is there somewhere in the body that can store fluid, apart from the bladder? Most nights I wake to empty my bladder after exactly 4 hours sleep, but on occasional nights where I haven’t been to the loo all day previously I have to get up three of four times instead of only once. It’s obvious that the urine has been building up during the day, but it wasn’t here in my bladder before I went to bed. So where was it?

Wednesday, 20 June 2007

Eyes of the world

I am a general practitioner with an interest in eyes. I would like to know why green eyes are so rare in the UK. And is there anywhere in the world where they are common?D. R. Piechowski, Kettering, Northamptonshire, UK

Wednesday, 6 June 2007

Life After Death

Why do hair and fingernails grow after death? Surely dead means dead. How can our bodies continue to produce more cells?

Shannon Smith, Bermuda

The following answers were selected and edited by New Scientist staff. You can add your replies in the comments section below.

This is something that we noticed as fresh-faced first-year medical students when confronted with the cadavers we were going to dissect over the next two years. All had slightly long fingernails, and all of the men had neatly cropped stubble. We assumed that these had grown while the cadaver was being prepared. However, an anatomy demonstrator assured us that nails and hair do not grow after death and that this phenomenon was actually the result of the surrounding tissue drying out and shrinking away from the nail folds and hair shafts, giving the impression of growth.David Pothier, Bristol, UK

This is a myth possibly spawned by Enrich Maria Remarque's novel All Quiet on the Western Front in which Paul Bäumer, the 19-year-old narrator, considers the death of his friend Kemmerich from gangrene. He writes: "It strikes me that these nails will continue to grow like lean fantastic cellar-plants long after Kemmerich breathes no more. I see the picture before me. They twist themselves into corkscrews and grow and grow, and with them the hair on the decaying skull, just like grass in a good soil, just like grass..."

Sorry to disappoint anybody, but hair and fingernails don't grow after death. Instead, our bodies dehydrate and our skin shrinks and tightens, pulling away from the hair and nails, creating the illusion of growth. Interestingly, funeral parlours put moisturiser on corpses to help reduce this effect.Richard Siddall, Harrow, Middlesex, UK

It is quite a common error to believe that fingernails and hair continue growing after death. Some time ago a person convicted of murder asked my library's information service for literature relating to the effect. He wanted to prove his innocence by relying on the post-mortem growth of hair and fingernails which would throw doubt on the timing of the killing. Unfortunately for the individual, no scientific verification for this growth exists.Baerbel Schaefer, Marburg University Library, Germany

Saturday, 19 May 2007

Organic Lingerie

I am a midwife and a mother, and recommend using cabbage leaves for swollen, painful breastfeeding breasts, milk suppression and mastitis. I tell affected women to line their bras with the cold leaves. It seems to work, but does anybody know why? Could the same treatment work for breast cysts?Cate Turner, Kendall, New South Wales, Australia

The following answers were selected and edited by New Scientist staff. You can add your replies in the comments section below.

Cabbage is part of European folk medicine and has been described as a poor man's poultice (see www.bmj.com/cgi/content/full/327/7412/451-c). If there are controlled trials of the healing power of cabbages, they are not easy to find - Ed

Cold cabbage leaves will have the simple effect of a cold compress, and reduce heat in the same way as a cold flannel might (but without the drips). However, the beneficial effects of the cabbage are increased if you heat the leaves, by running a hot iron over them or by blanching in boiling water, before applying. The heat releases various anti-inflammatory chemicals as well as phytohormones. Leaving the leaves in the bra will have a slow-release effect as the body warms them and draws out beneficial chemicals.

Hot cabbage poultices have also been used for sprains and strains and to draw out splinters. I used the above remedy to treat a breast abscess (a side-effect of mastitis) resistant to antibiotics. Greek women used vine leaves for the same purpose. It would be interesting to find out if the leaves have the same chemicals in them.Vivienne Tuffnell, Lowestoft, Suffolk, UK

Cabbages are members of the Brassicaceae, a large and diverse plant family. Among many other chemicals, brassicas produce glucosinolate compounds, one of which, sinigrin (potassium myronate), gives rise to the pungent smell associated with cooking cabbage.

In the presence of water and the brassica enzyme myrosinase, sinigrin forms "mustard oils", which are noted throughout history for their healing properties when applied as a poultice. Crushed or chopped leaves are applied externally as a counter-irritant to ease swellings and painful joints and to cleanse infections, and a warming sensation can be experienced in the skin. Mustard oils can lead to blistering, however, so must be used with caution.Richard Eden, Consultant botanist, Southampton, Hampshire, UK

Saturday, 10 February 2007

Three’s a crowd

In a clumsy effort to seduce her, I was trying to explain the evolutionary advantages of sexual reproduction to a female friend the other day, one of which I said was introducing an element of genetic competition into the process. She wanted to know why, if two sexes are needed to create genetic competition, why aren't there three, four or a million sexes to create even more competition? So why are there only two?

Saturday, 20 January 2007

A pox on us

Why aren't we concerned about a mild virus such as chickenpox mutating into something far worse, when there is such a fuss about the possibility of bird flu virus doing so? What is it about chickenpox that means it has remained stable down the centuries, while flu viruses have mutated almost yearly?

Thursday, 20 April 2006

Eye tones

I have different coloured eyes. When I look through my green eye the scene is yellower than that viewed through the brown eye which gives a more golden hue. Do we see colours differently depending on our eye colour?

Saturday, 22 October 2005

Wine whine

As little as half a glass of certain white wines causes me to feel very drunk and come out in a rash on my face and chest - and I feel very odd the next day. By a lengthy process of elimination, I have worked out that the culprits are always wines from South Africa. I don't react to wines from other countries. So why does South African wine cause this?

Saturday, 10 September 2005

Expect pain in knee area

I damaged my knee ligaments in a skiing accident about two years ago. Ever since then I have had what I describe as a "weather forecasting knee". Before it rains I always experience pain in my knee. This happens in both summer and winter and does not seem to be related to humidity. I am not the only person to have reported this. Why does my knee hurt before it rains and, more interestingly, how does it know? How does it detect the onset of rain?

Saturday, 3 September 2005

Organ farms

Human cells are continually dying and being replaced, but how much time does it take an entire organ, such as the liver, to replace itself? Also how long does it take to replace all the cells in the human skeleton, and how many times would this process be completed in an average lifespan?

Saturday, 14 May 2005

Flight sight

A few days ago, as the plane I was travelling in was manoeuvring and I was looking out of a window, the sun shone directly into my eyes. I shut my eyes but the sun had created a very strong "after-image", which was bright yellow with red edges, which was presumably in my retina. I kept my eyes closed and watched the after-image. Over a period of about 3 minutes, the central area changed from the initial bright yellow to bright green, then to a dull red and finally a faint, pale blue before disappearing. What did the colour sequence indicate?

Crucial cravings

I was diagnosed with cancer in 1994 and have been treated for several recurrences since. A pattern has emerged that, when I am having chemotherapy or am on high doses of steroids, I develop intense cravings for certain foods that I don't normally eat. These include a very high-fat diet, fried food (especially eggs) and a craving for ginger. There is a well-established timing to these cravings: I wake for a fatty food snack at 2 am and ginger around 4 am, for example. I also crave various vegetables in large amounts, and have bought several foods that I had never tasted before but knew immediately that I wanted when I encountered them in the supermarket. Interestingly, the relief I experience on eating the things I crave is instantaneous - there is no time for any absorption or metabolism to occur. Is my body telling me that it knows what it needs for the healing process to begin? Or is something else at work?

Saturday, 2 April 2005

Nasal illusion

If I tap my nose with my finger I only register a single touch, yet the sensation from nerves in my nose has only a few centimetres to travel to my brain, while the one from my finger tip has to travel about a metre up my arm and shoulder. Is this an illusion arranged by my brain, or is the brain unable to distinguish between two events so close together in time? Can anybody explain?

Saturday, 29 January 2005

I don’t like that!

As the parent of a toddler with the usual unpredictable food preferences, I wonder what would be the healthiest combination of three or four basic foods (plus water, of course). For example, how would a toddler cope on a diet of broccoli, cheddar cheese and oats?

Saturday, 14 August 2004

Complex colouring

I was taught at university that brown eyes were genetically dominant to blue eyes, and that two blue-eyed parents could not have a brown-eyed child, only one with blue eyes. I now understand that recent research has proved this to be untrue and that in some circumstances two blue-eyed parents can have a brown-eyed child. What has the new research uncovered and how does the newly discovered genetics work?

Saturday, 13 December 2003

Size matters

In discussions on family planning and HIV, one occasionally sees statistics such as "condoms work only x per cent of the time", where x is usually between 85 and 99. How is this number measured, and what sort of sample size is used?

Saturday, 20 September 2003

It’s not fair

My husband is in his fifties, weighs 105 kilograms, smokes, drinks and never, ever, takes any exercise. Yet his body is perfectly firm, no sagging whatsoever, very much like a freshly caught mackerel. The rest of us need incessant trips to the gym to avoid looking like jellyfish. Can his incredible luck be explained in biological terms? And given that a nice firm body is an obvious advantage in the breeding game, why isn't it more widespread?

The morning after

The Last Word explores the science of everyday things. Both the questions and the answers are provided by the smartest people we know – you, the New Scientist users. You can post your answers in the comments under each blog post. More about The Last Word.